<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<style type="text/css">
*{font-size: 14px; padding:0; margin:0;}
.main{
	position: relative;
	margin: 20px auto;
	border: 1px solid steelblue;
	width: 430px;
	height: 400px;
}
.msgInput{
	display: block;
	width: 406px;
	height: 60px;
	margin: 10px auto;
	
}
.sendbtn{
	position: absolute;
	width: 100px;
	height: 29px;
	bottom: 5px;
	right: 10px;
}
.content{
	list-style: none;
	width: 410px;
	height: 280px;
	margin: 5px auto;
	border: 1px dotted #D1D3D6;
	overflow-y: scroll;
}
.msgContent{
	width:auto;
	max-width: 250px;
	height: auto;
	word-break: break-all;
	margin: 5px;
	padding: 3px;
	border-radius: 5px;
}

.content .left{
	float: left;
	text-align: left;
	background-color: lightgrey;
}
.content .right{
	float: right;
	text-align: right;
	background-color: yellowgreen;
}


</style>
<script type="text/javascript" src="js/common.js" ></script>
<script type="text/javascript">
	window.onload=function(){
		var sendbtn = document.getElementById("sendbtn");
		var oUL = document.getElementById("content");
		var textArea = document.getElementById("msg_input");
		sendbtn.onclick = function(){
			var div = document.createElement("div");
			div.style = "clear: both;";
			
			var li = oUL.lastElementChild.cloneNode(true);
			var inputvalue = this.previousElementSibling.value; 
			li.innerHTML = inputvalue;
			
			oUL.appendChild(div);
			oUL.appendChild(li);
			
			textArea.value = "";//?
			
			li.scrollIntoView();//将目标元素滚动到可见的位置
		}
		
		textArea.onkeypress = function(e){
			var evt = e || event;
			var _key = evt.keyCode || evt.which;//IE使用keyCode  FF使用which
			if((_key == 13 || _key==10) && evt.ctrlKey){ //回车键 并且 按下ctrl
				var div = document.createElement("div");
				div.style.clear = "both";
				var li = oUL.lastElementChild.cloneNode(true);
				li.innerHTML = textArea.value;
				oUL.appendChild(div);
				oUL.appendChild(li);
				
				textArea.value = "";
				li.scrollIntoView();
			}
		}
	}
</script>

</head>

<body>
	<div id="main" class="main">
		<ul id="content" class="content">
			<li class="msgContent left">hello?</li>
			<div style="clear: both;"></div>
			<li class="msgContent left">hello</li>
			<div style="clear: both;"></div>
			<li class="msgContent right">hi</li>
			<div style="clear: both;"></div>
			<li class="msgContent left">hehe</li>
			<div style="clear: both;"></div>
			<li class="msgContent left">goodbye</li>
			<div style="clear: both;"></div>
			<li class="msgContent right">。。。。</li>
			<div style="clear: both;"></div>
			<li class="msgContent right">sdfasdsadfassdfsdfsdfdsfsdfsdfsdfdfasdffasdfasfdasd fasd fasd fasdfasdfasdf</li></ul>
		<textarea id="msg_input" class="msgInput"></textarea>
		<button id="sendbtn" class="sendbtn">发送</button>
	</div>

</body>
</html>
